<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>CSS盒子模型</title>
		<style>
			#f1{
				width: 480px;
				height: 480px;
				border: 1px solid red;
				padding-top: 50px;
				margin: 0 auto;
			}
			#f2{
				width: 260px;
				height: 260px;
				border: 10px solid cyan;
				margin-left: 50px;
				padding-top: 50px;
				margin: 0 auto;
			}
			
			#login{
				margin-left: 50px;
				margin-bottom: 30px;
			}
		</style>
	</head>
	<body>
		<div id="f1">
			<div id="f2">
				<button id="login">登录</button>
			</div>
		</div>
	</body>
</html>
